Clamping mechanism for pneumatically-operated pianos.



m N m mm i m m L W .n M W A v UNITED STATES PATENT OFFICE.

AXEL G. GULBRANSEN, OF- CBIGAGO, ILLlNOIS, ASSIGNOR T0 GULBRANSEN, DICKINSON COMPANY, OF CHICAGO, ILfiTNU-IS, A CORPORATION OF ILLINOIS.

OLAMPING FOR PHEU'MATICALLY-OPEBATED PIANOS.

Bpodfleaflon 01 Letters. Patent.

Patented Nov. 10, 1905.

5 of Illinois, have invented a certain new and useful Im rovenient in, Clampin Mechamsm for *neumatically-Operate Pianos, (Case 7,) of which the following is a fall,

ence being bad to the accompanying drawinfl, forming a part of this specification. y invention concerns improved clamping arrangement for use in pneumatically operated pianos.

My invention is of particular uti ity in pneumaticplaying pianos, in which the .arran emeht was disclosed in my Patent No. 874, 62 of December 24, 1907, in which the pneumatic actions are arranged in horizontal rows or tiers above' the keys and in front of the lower ends of the piano abstract rods, the neumatic actions engaging directly with a'utments secured to the abstract rods. It is very desirable that these abutment members he ada ted for ad- 'ustable en menttwith the a street rods. t is also esirable that they be applied in such manner that the abstract rods will not need to be disturbed or weakened, as, for

receiving screws, t is operation oftentimes resulting in splitting of the abstract rods.

My invention, therefore, contemplates a clamping arrangement which will not require any wear on the abstract rods and is in the form of clamps which embrace the abstract rods and the abutment members, each clamp being provided with a set screw for enga mg a ainst the abutment member, thus to rm y sump the abutment members against the rods.

In the accompanying drawingl igure 1 is a sectional view of a piano shelf and key compartment showing t e general arrangement of the pneumatic actions with reference to the abstract rods; Fig. 2 is a view taken from plane 2 2 of Fig. 1, showing the form of clamp.

The pneumatic actions a are mounted in horizontal rows or tiers from the rear wall of a low ressure chamber 6 extending across the interior of the piano. Each pneumatic action has an abutment extension 0 for en ging with the foot d of an abutment memr e, which abutment members are secured clear, concise, and exact description,- refer-' instance, by drillin holes into the rods for.

to the abstract rods f of the piano. To-

adjustably secure the abutment membersto the abstract rods clamps g are provided whose form is'best shown in Fig. 2. Each clamp is bent from sheet mater1al,-preferably of a springy nature, and is substantially U-shaped, comprising a front wall 1, side walls 2, 3 and the inwardly turned endsyt and-5. The front wall has a threaded opening for receiving a set screw 6. The side members 2 and 3 of the clampsare normally s rung inwardly a trifle so that they will c amp the abstract rod" to cause the clamp to be-self-sup orting.

When the a utment members are to be a plied two clamps are slip ed on each all .stract rod and over the a utment member for the abstract rod, which abutment members are in the-form of flat rods or plates htvlng the (same width as the abstract rods. ()ne of the clampsfis then moved to the lower end of the abstract rod and the other remains near the upper end. of the abutment member. The set screws 6 are normally loose enough to allow the abutment men'iber to be easily moved longitudinally. The pneumatic action mechanism being in place and the abutments c all in'proper normal position, each abutment member ismoved downwardly until .foot cl engages the abutment 0 extending from the associated pneumatic action member, whereupon the removed 8n( the lower set screws of the 'lower clamps tightened. Owing to the disosition of the pneumatic action members in liorizontal rows, the abutment feet (1 will be in different planes, but. the abutment rods I preferably make of different lengths so that when the abutment members have all been secured to the abstract rods the top ends thereof 'will all be in a horizontal line, and likewise the top clamps will all be in a horizontal line, which line is above the lane of the pneumatic action mechanisms. his renders the upper clamps accessible from the top of the pneumatic action mechanisms, and the first adjustment of the abutment members can be very readily made without disturbing the pneumatic action members.

I have sh own the abutment members passing through the clamps between the abstract rods and the set screws, but the clam s could be arranged so that the abstract r s would between the abutment members and the set screws so that the set screws will be ac-, cessible from the rear of the piano. The entire adjustment could then be made without disturbing the pneumatic actions or removing them from the instrument. Bythe use of these clamps no work is necessary on the abstract rods which" retain their original strength. Other clamps of the prior art require that the abstract rods be drilled for screw holes; and very frequently the grain will' run crosswise and the abstract rod cracked or split. The clamp also is very simple and inex ensive and its application requires very litt e labor.

Having thus described my invent1on, I desire to secure the following claims by Letters Patent 1. In a pneumatically operated piano, the combination of the abstract rods for the piano, pneumatic action mechanisms arranged withinthe piano casin in front of the ends of the abstract to s, abutment members for each abstract rod to be engaged by an associated pneumatic action mechanism so that upon actuation of the pneumatic action mechanism the abstract 'rod will be raised, and means for securing the abutment members to the abstract rods, said means being in the form of metallic U- shapedclamps which embrace the abstract rods and abutment members and which are 1 provided with set screws for locking them in position and for firmly clampin the abutmeut members to the abstract to s.

1 ends of the abstract rods, abutment members 2. In a pneumatically operat d piano,-the combination of the piano abstract rods, pneumatic action mechanisms arranged in front of the abstract rod ends and within the piano casing, abutment members for the abstract rods to be directly engaged by the pneumatic action members, a set of clamps for holding each abutment member to its abstract rod, one clamp engaging at the to of the abutment and the other at the end of the abstract rod, each clamp being in the form of a rectangular U-shaped member formed of sheet material, and a set-screw for clamping; the abutment member to the abstract ror 3. In a pneumatically operated piano, the combination of the piano abstract rods, pneumatic action mechanisms arranged within the piano casing in frontof the lower for connecting the pneumatic action mechanlsms direct y with the abstract rods, and

clamps for clamping each abutment mem-- within the piano casing in front of the lower ends of the abstract rods, abutment members for connecting the pneumatic action mechanisms directly with the abstract rods, clamps for clamping each abutment member to its abstract rod,-each clamp comprising a U-shaped body part for embracing the abstract rod and abutment rod, the ends of the body part bein turned inwardly, and a set screw passing tIirough the head ,of the body part for engaging with and clamping together the abutment member and abstract rod within the body part; the body part walls bein sprung inwardly so that. the clamps wil self-support themselvest'on the abstract rod before the screws are set.

5. In a pneumatically operated piano, the

combina'tion'of'the abstract: pneumatic action mechanisms'arranged m' out of the abstract rod, spring clamps normally em-' bracing the abstract rod and having a passageway through which the abutment mem-- ber may slide to be adjusted with reference to the pneumatic action mechanism, and a set screw for each spring clamp for permanently securing the abutment member to the abstract rod. I Y

In witness whereof, I hereunto subscribe my name this 18th day of February, A. D.

AXEL' G. GULBRANSEN- Witnesses;

LEONARD W. NovANnnR, CHARLES J. SoHMm'r.

90 lower'en'ds of the abstract rods, clamps en- 

